Does triggering Art 50 mean Brexit?

The Liberal Democrats, with +20,000 members since the ref and the highest number of members since 1993 (but still at 8-9% in the opinion polls) have pledged that they will offer the British people a referendum on the final Brexit deal.

One detail though: Once Article 50 has been invoked, it cannot be revoked. Thus the new ref can be on the type of Brexit deal not on Brexit per se.

Now, friends have argued that  various legal opinions are around on that issue and that the author of the actual Article 50, as well as members of the ECJ have said that there is nothing in any of the treaties that says a member state can't withdraw its intention to leave the EU after invoking Art.50 and before the 2 year time period is up.

Well, while I fully understand the predicament the EU cannot spend years negotiating a deal and then have the whole thing scrapped. Plus, by the next UK elections (2020), it will be all over, the triggering and the two years. The issue is to avert the triggering and that can happen if the current government gets a no confidence vote.